Flash memory is non-volatile, which means that it stores information so that the memory does not need power to maintain the information. Flash memory data may be stored in floating gates (FGs), which are part of a field effect transistor (FET), and which gates are relatively isolated from other structures in a semiconductor device. The floating gates may be based on the floating-gate avalanche-injection metal oxide semiconductor (FAMOS transistor) which is essentially a complimentary metal oxide semiconductor (CMOS) FET that includes the FG isolated between the gate and source/drain terminals.
The pressure upon the microelectronic device fabricator to ever miniaturize, motivates reducing the size of back-end-of-line (BEOL) structures such as the metallization.